Rotating paddle bin level indicator

Abstract

Apparatus for indicating the level of flowable material in a storage bin comprising a motor mounted within a protective enclosure and coupled by a shaft to a paddle disposed within the bin to engage material contained therein. When the material reaches the level of the paddle, drag on the paddle causes the motor to rotate within the enclosure and thereby to activate switches disposed within the enclosure for indicating material level. A spring is mounted between the enclosure and the motor such that the spring urges the motor to both the switch-activating and the switch-deactivating positions in turn, and must be urged over center to permit motion of the motor in either direction between such positions.

The invention claimed is: 
     
       1. Apparatus for indicating level of material in a storage bin comprising a hollow enclosure including means for mounting said enclosure to a storage bin, a motor mounted for limited movement within said enclosure between first and second positions, a paddle operatively coupled to said motor and constructed to be disposed for rotation within said bin, rotation of said paddle being retarded when material stored in said bin is at a level so as to stallably engage said paddle, means mounted in fixed position within said enclosure for detecting limited movement of said motor between said first position when rotation of said paddle is not retarded by material stored in the bin and said second position when rotation of said paddle is retarded by material stored in said bin, and spring means extending between means projecting from said motor and means affixed to said enclosure for urging said motor to both said first and second positions such that said spring means must be urged over center during motion of said motor in either direction between said first and second positions. 
     
     
       2. The apparatus set forth in claim 1 wherein said means affixed to said enclosure comprises a bracket, and where said spring means comprises a coil spring, a rocker mounted to pivot on said bracket between first and second positions corresponding to said first and second positions of said motor, and means for mounting said coil spring to said rocker and bracket such that said spring must be urged over center during motion of said motor in either direction between said first and second positions. 
     
     
       3. The apparatus set forth in claim 2 wherein said coil spring is mounted to said rocker and said bracket such that the axis of said spring intersects the pivot axis of said rocker midway between said first and second positions of said rocker, and wherein said means projecting from said motor engages said rocker so as to pivot said rocker during motion of said motor. 
     
     
       4. The apparatus set forth in claim 3 wherein said means projecting from said motor comprises lost motion means, such that initial motion of said motor from either said first or second position causes no corresponding pivotal motion of said rocker. 
     
     
       5. The apparatus set forth in claim 4 wherein said lost motion means comprises an aperture in said rocker an an arm projecting from said motor into said aperture.